Journal of Physical Organic Chemistry最新文献

{"title":"Changes in mechanism and transition state structure for solvolysis reactions of ring substituted benzyl chlorides in aqueous solution","authors":"Paul E. Yeary,&nbsp;John P. Richard","doi":"10.1002/poc.4600","DOIUrl":"10.1002/poc.4600","url":null,"abstract":"<p>Rate and product data are reported for the solvolysis reactions of 27 mono, di [3,4] and tri [3,4,5] ring-substituted benzyl chlorides. The first order rate constant for solvolysis in 20% acetonitrile in water decrease from <i>k</i>_solv = 2.2 s⁻¹ for 4-methoxybenzyl chloride to 1.1 × 10⁻⁸ s⁻¹ for 3,4-dinitrobenzyl chloride. The product rate constant ratios <i>k</i>_MeOH/<i>k</i>_TFE for solvolysis in 70/27/3 (v/v/v) HOH/TFE/MeOH range from a minimum of <i>k</i>_MeOH/<i>k</i>_TFE = 8 to a maximum of 110. The rate data were fit to a four-parameter Hammett equation that separates the resonance (\u0000<span></span><math>\u0000 <msub>\u0000 <mi>ρ</mi>\u0000 <mi>r</mi>\u0000 </msub>\u0000 <msub>\u0000 <mi>σ</mi>\u0000 <mi>r</mi>\u0000 </msub></math>) and polar (\u0000<span></span><math>\u0000 <msub>\u0000 <mi>ρ</mi>\u0000 <mi>n</mi>\u0000 </msub>\u0000 <msub>\u0000 <mi>σ</mi>\u0000 <mi>n</mi>\u0000 </msub></math>) effects of the aromatic ring substituents on the reaction rate. Increases in the values of the Hammett reaction constants \u0000<span></span><math>\u0000 <msub>\u0000 <mi>ρ</mi>\u0000 <mi>r</mi>\u0000 </msub></math> and \u0000<span></span><math>\u0000 <msub>\u0000 <mi>ρ</mi>\u0000 <mi>n</mi>\u0000 </msub></math> are observed as the substituent constants \u0000<span></span><math>\u0000 <msub>\u0000 <mi>σ</mi>\u0000 <mi>r</mi>\u0000 </msub></math> or \u0000<span></span><math>\u0000 <msub>\u0000 <mi>σ</mi>\u0000 <mi>n</mi>\u0000 </msub></math> are increased. A sharp decrease in the product selectivity <i>k</i>_MeOH/<i>k</i>_TFE = 26 for stepwise solvolysis of 4-methoxybenzyl chloride is observed as electron-withdrawing <i>meta-</i>substituents are added to 4-methoxybenzyl ring due to a Hammond-effect on the position of the transition state for solvent addition to the substituted 4-methoxybenzyl carbocation reaction intermediates. Sharp increases in the selectivity <i>k</i>_MeOH/<i>k</i>_TFE are observed with decreasing reactivity of other 3,4,5-subsituted benzyl chlorides due to anti-Hammond shifts, on a two-dimensional More–O'Ferrall reaction coordinate diagram, in the position of the transition state for a concerted solvolysis reaction.</p>","PeriodicalId":16829,"journal":{"name":"Journal of Physical Organic Chemistry","volume":"37 7","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139925508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantum chemical explanation and APT atomic charge index of substituent orienting effect proposed by DFT calculation and MO Theory","authors":"Hongchang Shi","doi":"10.1002/poc.4580","DOIUrl":"10.1002/poc.4580","url":null,"abstract":"<p>In organic chemistry textbooks, the electron resonance states are used to explain the orienting effect of benzene substituent. However, these resonance states do not exist in the C₆H₅-S + E⁺ electrophilic addition, so the resonance state discussions actually are meaningless. The density functional theory (DFT) calculation shows that the C₆H₅-S + E⁺ addition follows the transition state theory and needs to overcome a barrier. Benzene molecule C₆H₆ has two degenerate highest occupied molecular orbitals (HOMOs), but after becoming substituted benzenes, the two HOMOs split to HOMO and HOMO-1 with different orbital energies and electron distributions. It makes the addition barrier on two or three benzene ring carbons is low, and the addition rate is fast, but the barrier of other carbons is high, and the rate is slow. Therefore, substituent splits the two degenerate HOMOs of benzene molecule, which is the origin of substituent orienting effect. For the substituted benzenes with halogen group -X and electron-releasing group, their HOMO images alone can determine that the two types of substituents are the ortho- and para-orienting groups, but for the substituted benzenes with electron-withdrawing group, their HOMO alone cannot determine whether the substituent is a meta-orienting group. The study found that atomic polar tensor (APT) charges are a good judgment index of substituent orienting effect because based on its physic-chemical model, the charges represent the number of active electrons on the benzene ring carbons. The DFT calculation gives the APT charges of 19 mono-substituted and 12 di-substituted benzenes and some aromatic molecules. The APT charges can all correctly determine their orienting effects, showing that APT atomic charge from quantum theoretical calculation is a good substituent orienting index.</p>","PeriodicalId":16829,"journal":{"name":"Journal of Physical Organic Chemistry","volume":"37 6","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139777642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Innovative and sustainable synthesis and structure of novel N-substituted hexahydroacridine derivatives","authors":"Nangagoundan Vinoth,&nbsp;Chinnasamy Kalaiarasi,&nbsp;Appaswami Lalitha","doi":"10.1002/poc.4604","DOIUrl":"10.1002/poc.4604","url":null,"abstract":"<p>An efficient and green synthesis of tetramethyl-10-(phenylamino)-3,4,6,7,9,10-hexahydroacridine-1,8(2<i>H</i>,5<i>H</i>)-dione derivatives has been achieved from various substituted aryl aldehydes, 5,5-dimethyl-3-(2-phenylhydrazinyl)cyclohex-2-enone and dimedone in aqueous ethanol medium. Environment-friendly reaction, excellent yields, operational simplicity and shorter reaction times are the significant features of the present protocol. All the synthesized compounds were characterized by various spectroscopic techniques and X-ray crystal diffraction studies.</p>","PeriodicalId":16829,"journal":{"name":"Journal of Physical Organic Chemistry","volume":"37 5","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139838512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recognition of histidines with a synthetic zinc amino-oxochlorin regioisomer via synergetic coordination and hydrogen bonding","authors":"Mio Yuasa,&nbsp;Nobuyuki Hara,&nbsp;Hitoshi Tamiaki","doi":"10.1002/poc.4602","DOIUrl":"10.1002/poc.4602","url":null,"abstract":"<p>Zinc 13-(<i>N</i>,<i>N</i>-diethylamino)methyl-3,3,7,8,12,17,18-heptaethyl-2-oxochlorin was prepared from 2,3,7,8,12,13,17,18-octaethylporphyrin via the regioselectively acid-catalyzed double dehydration of <i>cis</i>-12,13-diethyl-<i>cis</i>-12,13-dihydroxy-2-oxobacteriochlorin to the corresponding 12-ethyl-13-vinyl-2-oxochlorin. The synthetic zinc amino-oxochlorin was axially ligated with the imidazolyl group of <i>N</i>^α-protected histidines in chloroform, and concomitantly the amino group of the former was hydrogen-bonded with the carboxy group of the latter. The resulting two-point bonding supramolecules served as models for the complexes of chlorophylls with peptides in photosynthetic apparatuses including light-harvesting antennas and charge-separating reaction centers. A similar 1:1 complex was produced by the interaction of the zinc amino-chlorin with the related methionine possessing thioether and carboxylic acid moieties.</p>","PeriodicalId":16829,"journal":{"name":"Journal of Physical Organic Chemistry","volume":"37 4","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139656553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Better performances of benzene-based over thiophene-based aromatic anionic donors: Computational studies on metameric conformational selectivity and hyperpolarizability of organic inner salts","authors":"Sanyasi Sitha","doi":"10.1002/poc.4598","DOIUrl":"10.1002/poc.4598","url":null,"abstract":"<p>Earlier experimental works report the synthesis of zwitterions with anionic <i>p</i>-dicyanomethanide (coupled to benzene and thiophene) donors. In this report, four such zwitterions (two metameric pairs) are investigated using HF, B3LYP, CAM-B3LYP, HSE06, and ωB97xD methodologies. This work is focused on (1) <i>metameric</i> (<i>Reichardt's and Brooker's</i>) <i>induced conformational selectivity</i> (<i>twisted</i> vs. <i>planar</i>) and (2) <i>efficiency assessments of benzene-</i> versus <i>thiophene-based anionic donors</i>. These effects were found to have significant influences on many tensorial and nontensorial properties. For Reichardt's type, large twisting was observed for the benzene case and lower twisting for the thiophene case. Enhanced first hyperpolarizability were observed for Reichardt's type (257.2 × 10⁻³⁰ esu) than Brooker's type (67.2 × 10⁻³⁰ esu), thus indicating the former type to be more efficient (<i>approximately fourfold enhancement</i>) chromophore (<i>approximately seven-time enhancement</i> for <i>thiophene-based</i> systems). Similarly, between the benzene versus thiophene cases, enhanced hyperpolarizabilities were observed for the former (257.2 × 10⁻³⁰ esu) than the latter type (112.0 × 10⁻³⁰ esu), indicating the benzene type as more efficient (<i>more than twofold enhancement</i>) donor (<i>approximately four-time enhancement</i> for <i>Brooker's types</i>). The structure–property manipulations strategies investigated here can be used as valuable tools in the designing of efficient functional molecular materials for various fundamental applications.</p>","PeriodicalId":16829,"journal":{"name":"Journal of Physical Organic Chemistry","volume":"37 4","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/poc.4598","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139616457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Retraction: Exploring the intermolecular interactions in carbon disulfide dimer: An ab initio study using an improved Lennard–Jones potential energy surface for physical insights","authors":"","doi":"10.1002/poc.4597","DOIUrl":"https://doi.org/10.1002/poc.4597","url":null,"abstract":"<p>Waqas Amber Gill¹ | Muhammad Usman Khan² | Zunaira Shafiq³ | Muhammad Ramzan Saeed Ashraf Janjua³</p><p>Gill, W. A., Khan, M. U., Shafiq, Z., Janjua, M. R. S. A., “Exploring the Intermolecular Interactions in Carbon Disulfide Dimer: An Ab Initio Study Using an Improved Lennard-Jones Potential Energy Surface for Physical Insights,” J Phys Org Chem 2023, https://doi.org/10.1002/poc.4548. The above article, published online on 05 June 2023 on Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the journal's Editor in Chief, Professor Rik Tykwinski, and John Wiley and Sons LLC. The journal's Editor-in-Chief was contacted by a third party who raised concerns about the article. An independent scientific expert evaluated the article and confirmed that significant problems exist with the data and conclusions of the work, and that it contains inadequate and/or inaccurate citations. As a result, the editors consider the article's conclusions to be unreliable.</p>","PeriodicalId":16829,"journal":{"name":"Journal of Physical Organic Chemistry","volume":"37 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/poc.4597","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139419667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sequence effects on the thermal cis–trans isomerization of side-chain stearate-containing azobenzene polymers","authors":"Md Sahanawaz,&nbsp;Manik Lal Maity,&nbsp;Krishna Gopal Goswami,&nbsp;Pintu Sar,&nbsp;Priyadarsi De,&nbsp;Subhajit Bandyopadhyay","doi":"10.1002/poc.4599","DOIUrl":"10.1002/poc.4599","url":null,"abstract":"<p>Photochromic azobenzenes undergo light-mediated <i>trans</i>–<i>cis</i> isomerization. The <i>cis</i> isomer reverts to the <i>trans</i> isomer thermally. To investigate the effect of different monomer sequences on the thermal stability of <i>cis</i>-azobenzene, a series of copolymers, namely, block, and random structures containing stearic acid and azobenzene moieties as their side chains have been synthesized through reversible addition–fragmentation chain transfer (RAFT) polymerization. In this study, we investigate the photoisomerization of the <i>trans</i> and <i>cis</i> forms of the polymers and also the thermal reversal of the <i>cis</i>-azobenzene photochromic systems. The isomerization data revealed significant differences in the isomerization timescales between the polymers and the corresponding monomer. It was observed that the local polarity around the azobenzene units within a polymer was significantly influenced by the chain segment depending on whether it was in the vicinity of the hydrophobic alkyl chains or other azobenzene units. This local environment of the azobenzene units regulates the stabilization of the transition states during the <i>cis–trans</i> thermal isomerization, consequently affecting the half-life of the <i>cis</i> isomer.</p>","PeriodicalId":16829,"journal":{"name":"Journal of Physical Organic Chemistry","volume":"37 4","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139444106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electronic structure of 1,3-diphenyl-2-azaallenyl radical cation","authors":"Daniel Yim,&nbsp;Young-Kwan Kim,&nbsp;Ji Hun Park,&nbsp;Hyungjun Kim","doi":"10.1002/poc.4590","DOIUrl":"10.1002/poc.4590","url":null,"abstract":"<p>Quantum chemical simulations were conducted to elucidate the electronic structure of the 2-azaallenyl radical cation, a key intermediate in several [3 + 2]-cycloadditions initiated by the oxidation of 2H-azirine. We propose one additional Lewis structure in resonance with the commonly accepted two Lewis structures for the model system of 1,3-diphenyl-2-azaallenyl radical cation, drawn from comprehensive theoretical data including molecular shape, bond order analysis, partial atomic charges, and spin densities. In addition to the ground state chemistry, the chemical structure of excited state species can be also understood with these three Lewis structures. Theoretical data imply that a newly suggested one mainly accounts for the ground state structure, and the excited state structure is better represented by the previously reported ones. Our claim is further bolstered by the prediction of the excited state geometries of the dicationic and neutral species. This research presents the extended set of Lewis structures for a better understanding electronic structure of 2-azaallenyl radical cation.</p>","PeriodicalId":16829,"journal":{"name":"Journal of Physical Organic Chemistry","volume":"37 4","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139065053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reaction mechanism of acetonitrile, olefins, and amines catalyzed by Ag2CO3: A DFT investigation","authors":"Bin Chen,&nbsp;Da-Gang Zhou,&nbsp;Li-Jun Yang","doi":"10.1002/poc.4594","DOIUrl":"10.1002/poc.4594","url":null,"abstract":"<p>The mechanism of Ag₂CO₃-catalyzed reactions of acetonitrile, olefins, and amines was investigated by using the M06-L-D3/6-311 + G(d,p) method and level, and solvation model based on solute electron density (SMD) model was applied to simulate the solvent effect. Calculations show that the Ag₂CO₃ could achieve the Csp³-H activation by coordinating with the terminal nitrogen atom of CH₃CN; then, the addition reaction happened between the obtained Ag-complex intermediate and olefin via the coordination of Ag and benzene ring; finally, the obtained radical intermediate continues to go through one single electron transfer (SET) process, addition reaction, and H-shift reaction to yield the final product. The computational results reveal that Fe³⁺ cation would have assisted the SET process successfully and the path of direct addition with the amine is the optimal. Fukui function and dual descriptor can be used to predict the reactive sites, and electron spin density isosurface graphs can analyze the structures and reveal the substances.</p>","PeriodicalId":16829,"journal":{"name":"Journal of Physical Organic Chemistry","volume":"37 3","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139065010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"One-pot synthesis, thermal analysis, and density functional theory study of methyl urotropine perchlorate","authors":"Meihua Zhao,&nbsp;Jun Cao,&nbsp;Jun Chen,&nbsp;Jiani Xu,&nbsp;Tingting Xiao,&nbsp;Peng Ma,&nbsp;Congming Ma","doi":"10.1002/poc.4595","DOIUrl":"10.1002/poc.4595","url":null,"abstract":"<p>An energetic material methyl urotropine perchlorate (MUTP) was synthesized from urotropine, perchloric acid, and triethylenediamine. The single crystal structure of the energetic salt was characterized by X-ray single crystal diffractometer. The results show that the single crystal of MUTP is an orthogonal crystal system with Pnma space group. The thermal decomposition process of MUTP was studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) technology. There were two exothermic peaks in TGA and DSC test, and the peak temperatures (<i>T</i>_p) were 261.61°C and 366.75°C, respectively. The thermal stability of MUTP was up to 247.10°C. Geometric optimization, frontier molecular orbitals, electrostatic potential (ESP), and weak interaction were explored by density functional theory using Gaussian 16. It is found that MUTP has a large energy gap (5.94 eV), which is larger than that of HMX (5.84 eV). The results of reduced density gradient method show that there are dense hydrogen bond interactions in MUTP with high electron density and intensity. In addition, a strong spatial repulsion is formed at the center of the cage.</p>","PeriodicalId":16829,"journal":{"name":"Journal of Physical Organic Chemistry","volume":"37 3","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139036886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}